Design of a data-acquisition system for monitoring sleep organization in preterm infants

A portable data-acquisition system suitable for long-term noninvasive monitoring of physiologic and behavioral variables in preterm infants is described. The system includes two video cameras, a video screen-splitter and amplifier, a time-lapse video recorder, a microphone, a force-responsive transducer, an analog signal conditioner, and two microcomputers. One microcomputer, located in the neonatal intensive care unit (NICU) acquires electrophysiologic signals and preprocesses data in real time, during a continuous 48-hour session. After each session, the data file is transferred by telephone line to the other microcomputer, located in a laboratory, for editing, reduction, display, and final analysis. This arrangement enables noninvasive and nonintrusive monitoring, which is crucial for long-term recording of sleep-wake state organization of preterm infants.